All ETDs from UAB

Advisory Committee Chair

Nada Souccar

Advisory Committee Members

Andre Ferreira

Amjad Javed

Christos Vlachos

Document Type


Date of Award


Degree Name by School

Master of Science (MS) School of Dentistry


Introduction: The purpose of this retrospective study is to evaluate the maxillary and mandibular expansion achieved with Invisalign First (Align Technology, San Jose, CA) in growing children. Methods: Clinical stereolithography (STL) models of 32 patients in the mixed dentition stage, treated with the Invisalign First, were extracted from the ClinCheck software and analyzed in Dolphin imaging (version 11.95 Premium, Chatsworth, Calif) at three timepoints: T1 (initial records), T2 (virtual outcome prediction), and T3 (achieved outcome). The recorded measurements included: upper and lower primary intercanine and permanent intermolar width, upper and lower primary intercanine and permanent intermolar gingival width, upper arch perimeter, and upper arch depth. Results: Out of the 10 measurements evaluated, 8 showed a mean increase from T1-T3 (Initial-Final) and a decrease from T2-T3 (Prediction-Final). The upper deciduous intercanine gingival width (UICGW) showed the largest increase (+2.92 mm with 56.24% of planning accuracy). The least amount of expansion was found at the upper permanent intermolar gingival width (UIMGW) which showed the lowest percentage of accuracy. Conclusions: Clinically, the upper and lower transverse dimensions increased. The upper and lower primary intercanine distances showed the largest changes while the movement of the maxillary permanent molars was not significant. Clear aligners seem to be a good option for arch expansion in cases of mild to moderate transverse discrepancies in growing individuals. They appear to iv modify arch form to a broader shape, mostly in the anterior segments, thus providing space to alleviate crowding and help with malocclusion correction.

Included in

Dentistry Commons



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